a11y: add aria-label to interactive elements missing them

[ulises-jeremias]

Describe the feature

Audit header/footer/catalog controls for missing accessible names; add aria-label/aria-labelledby.

Use Case

Screen reader users hit unlabeled icon buttons.

Proposed Solution

Fix in layout-shell and catalog controls; verify with axe or keyboard pass.

Other Information

Maintainer-seeded Hacktoberfest issue.

Acknowledgements

• I may be able to implement this feature request
• This feature might incur a breaking change

Version used

website @ main

Environment details (OS name and version, etc.)

n/a (docs/site contribution)